Technical Field
The present invention relates to a touch panel, more specifically to a touch panel with a frame region narrowed.
Related Art
FIG. 24 is a cross-sectional view of a conventional touch panel 60. An upper electrode substrate 62 having a plurality of X-direction transparent electrodes 61 on a lower surface thereof and a lower electrode substrate 64 having a plurality of Y-direction transparent electrodes 63 on an upper surface thereof are being laminated via an adhesive layer 65. The plurality of X-direction transparent electrodes 61 are oppositely faced to the plurality of Y-direction transparent electrodes 63 with an adhesive layer 65 placed between. A plurality of X-direction drawn-round wires 66 are arranged on the lower surface of the upper electrode substrate 62. A plurality of Y-direction drawn-round wires are arranged on the upper surface of the lower electrode substrate 64. FIG. 24 does not, however, indicate the plurality of Y-direction drawn-round wires.
FIG. 25 is a layout drawing of a plurality of X-direction transparent electrodes 61 and a plurality of X-direction drawn-round wires 66 formed on a lower surface of the upper electrode substrate 62 of the conventional touch panel 60 (For instance, JP 5084698 B2). While the plurality of X-direction transparent electrodes 61 and the plurality of X-direction drawn-round wires 66 should originally be indicated in a broken line due to being arranged on the lower surface of the upper electrode substrate 62, the X-direction transparent electrodes 61 and the X-direction drawn-round wires 66 are indicated in a solid line to facilitate visualization.
In each of the X-direction transparent electrodes 61, a large number of diamond-shaped transparent electrode patterns 61a are electrically connected to a plurality of connecting electrodes 61b each having a small width in an X direction (lateral direction) and are aligned in a lateral direction of the touch panel 60. A large number of (for instance, 30) X-direction transparent electrodes 61 are aligned parallel to a longitudinal direction of the touch panel 60. X-direction transparent electrodes 61 are referred to as a first line, a second line, and a third line or the like from the top.
Each X-direction drawn-round wire 66 is connected to each X-direction transparent electrode 61. Accordingly, the X-direction drawn-round wires 66 are as many as the X-direction transparent electrodes 61. For instance, the number of the X-direction transparent electrodes 61 is 30, the number of the X-direction drawn-round wires 66 is also 30. For the purpose of illustration, FIG. 25 shows an example that the number of the X-direction transparent electrodes 61 is 8 and the number of the X-direction drawn-round wires 66 is 8.
As shown in FIG. 25, No. 1 X-direction drawn-round wire 66 is connected to an X-direction transparent electrode 61 on the first line. No. 2 X-direction drawn-round wire 66 is connected to an X-direction transparent electrode 61 on the second line. Similarly, No. 8 X-direction drawn-round wire 66 is connected to an X-direction transparent electrode 61 on the eighth line.
As shown in FIG. 25, No. 1 to No. 8 X-direction drawn-round wires 66 are arranged on a lower surface of the upper electrode substrate 62.
In the case of FIG. 25, when the wire width (line) and the wire space of the X-direction drawn-round wires 66 are each L (μm), S (μm), the lateral width of the area of the X-direction drawn-round wires 66 placed on the lower surface of the upper electrode substrate 62 needs to be at least (8L+7S) (μm).
FIG. 26 is a layout drawing of a plurality of Y-direction transparent electrodes 63 and a plurality of Y-direction drawn-round wires 67 formed on an upper surface of the lower electrode substrate 64 of the conventional touch panel 60. In each Y-direction transparent electrode 63, a large number of diamond-shaped transparent electrode patterns 63a are electrically connected to each other by a large number of connecting electrodes 63b each having a small width in a Y-direction (longitudinal direction) and are aligned in a longitudinal direction of the touch panel 60. A large number of (for example, 40) Y-direction transparent electrodes 63 are aligned parallel to a lateral direction of the touch panel 60. The Y-direction transparent electrodes 63 are referred to as a first row, a second row, a third row, a fourth row and so on from left. Transparent electrode patterns 63a in one Y-direction transparent electrode 63 are arranged in a blank portion surrounded by four transparent electrode patterns 61a of X-direction transparent electrodes 61. More specifically, the upper electrode substrate 62 is adhered to the lower electrode substrate 64 so that the transparent electrode patterns 61a of the X-direction transparent electrodes 61 may not be overlapped with the transparent electrode patterns 63a of the Y-direction transparent electrodes 63.
Each Y-direction drawn-round wire 67 is connected to each Y-direction transparent electrode 63. Accordingly, the number of the Y-direction drawn-round wires 67 is the same as the number of the Y-direction transparent electrodes 63. For instance, when the number of the Y-direction transparent electrodes 63 is 40, the number of the Y-direction drawn-round wires 67 is also 40. FIG. 26 illustrates an example in which the number of the Y-direction transparent electrodes 63 is 10 and the number of the Y-direction drawn-round wires 67 is 10.
As shown in FIG. 26, No. 1 Y-direction drawn-round wire 67 is connected to Y-direction transparent electrodes 63 on the first row. No. 2 Y-direction drawn-round wire 67 is connected to a plurality of Y-direction transparent electrodes 63 on the second row. As mentioned above, No. 10 Y-direction drawn-round wire 67 is connected to a plurality of Y-direction transparent electrodes 63 on the tenth row.
As shown in FIG. 26, No. 1 Y-direction drawn-round wire 67, No. 2 Y-direction drawn-round wire 67, . . . No. 10 Y-direction drawn-round wire 67 are arranged on the upper surface of the lower electrode substrate 64.
When a finger approaches to the touch panel 60, capacitance or the like in the X-direction transparent electrodes 61 and the Y-direction transparent electrodes 63 varies. X-coordinate and Y-coordinate of the position of the finger are detected by the detection of such electrical changes while switching a signal to be transmitted to each electrode. Detection methods include a self-capacity method and a mutual capacity detection method.
A touch panel is used in combination with a liquid crystal panel. Since frames of liquid crystal panels have been narrowed, frames of touch panels also need to become narrowed. At present, the narrowing of liquid crystal panels is prominent in left and right sides thereof. When the left and right frames of the touch panels become narrowed in accordance with the narrow frames of the liquid crystal panels, the area of drawn-round wires housed in the frame portions of the touch panels runs short.
For instance, when the number of the X-direction transparent electrodes and the X-direction drawn-round wires is respectively 30, the X-direction drawn-round wires each have a wire width (line) of 30 μm and a wire space of 30 μm, the area of each of the drawn-round wires needs to have a lateral width of about 2 mm. This makes the lateral width of the area of the drawn-round wires becomes smaller, resulting in impossible to use the drawn-round wires. However, there is a limit for making the wire width and the wire space smaller.